Glow plugs on-How long is too long?

[raunch]

The truck had been sitting for a few a hours on about a 30* day. Went to start it back up and the glow plug light stayed on for maybe 1/2 minute. It's never stayed on that long, even before the morning cold start. I got a little nervous and turned the key off. Turned the key on again, the light came on for a few seconds, and the motor started right up. Could this be an indicator that the controller is going out? How long can glow plugs stay on without damage?
Thanks.

[More Power]

The 1982-84 glow controllers weren't the best design. It is fairly easy to convert to the much better 1985-93 style.

The newest AC-60G glow plugs can remain on for hours without damage (though this could shorten their life somewhat). The original AC-9G glow plugs will burn out in 15-20 seconds of continuous glow time, and then present the possibility of losing a tip into the combustion chamber.

Jim

[nlines]

What years have the AC-60G glow plugs stock from the factory?

[raunch]

Thanks for the info. It's only happened that one time, but I'm watching them......